Vehicles such as combines operate in dusty, dirty conditions that require engine cooling and intake air to be clean from debris found in the environment in which they typically operate. To deal with these conditions, most combines use a rotary screen, which consists of a rotating screen with a vacuum duct on the outside of the screen. The screen acts to keep debris from entering the engine along with the cooling and intake air while the duct has a suction flow that removes debris from the screen as it rotates under it. This system works very well for most applications but has the limitation of blocking airflow to the corners of the cooling cores that are not located directly in the middle of the screen. The cores located near the outsides of the screen then have decreased cooling capacity. Therefore a mechanism is necessary that removes debris from the engine cooling and intake air and allows complete exposure of cooling air to the cores.